This is my first foray into Mira Grant's (aka Seanan McGuire) horror/sci-fi books, but it certainly isn't going to be the last. Hours after finishing Overgrowth, I've been sat in a daze trying to wrap my mind around what I just read. Think War of the Worlds meets Little Shop of Horrors.

Anastasia Miller is not the original Anastasia Miller. At the age of three, the original Anastasia was eaten by a carnivorous plant-alien that had crashed landed in the Pacific Northwest, and was replaced by THIS Anastasia. And she will happily tell that to anyone who asks that she is the vanguard of an approaching alien armada. The problem is that no one (with maybe the sole exceptions of her best friend and boyfriend) will believe her. That's about to become more of a problem for Earth when a scientist in Maine intercepts an alien signal from space, while Stasia's dreams of a communal forest space become more and more pushy.

This book was hilarious and horrific and gross and optimistic and I've just been babbling about it to anyone who will listen (and even some who won't) because it just became stuck in my brain. Fitting, for a book about parasitic carnivorous plants from space. I had a few expectations going into this book - after all, an alien raised on Earth as a human must surely be Team Earth, right? And we all know Earth always wins in these stories. But everything I thought was going to happen was turned on its head and I'm still amazed and baffled. A lot of that comes from letting the alien be the narrator of the story; the entire perspective is changed and I love that choice for this particular book.
Stasia as a narrator is hilarious: from her cat named Seymour, her collection of nerdy shirts (and friends), and her loving but ambivalent perspective on Earth, she's a unique point of view to follow. And the emphasis in the story on her found family was something special too: her boyfriend, a trans herpetologist named Graham, and her best friend, Mexican-American Mandy. In particular, her relationship with Graham is so lovely, transcending tragedy and species to be entirely unconditional even in the face of such horrors. Other characters, like the antagonists and secondary protagonists like David and Lucas, get a little lost in the shuffle or are very stock-like, but the strength of those main few outweighs all of the negatives.

My only complaint was that the book got a little clunky in the middle, a little too technical on the alien-transformation aspects, when I was ready to just get on with the invasion. And also, I really want to know about Seymour. But otherwise this was a delightfully horrific read!

The narrator was the perfect choice for this particular book, bringing so much life and nuance to Anastasia and the other characters!

Mira Grant has become my go-to author for scifi horror. No one does it like she does!

I have not read an alien invasion story and it was not a fear of mine before reading Overgrowth but here we are. The horror of this story comes from the tension building up and the realization as a reader that this is not so far fetched. I also loved a lot of the commentary and you can tell Grant put a lot of thought into this story.

I also appreciated our characters and their dynamics. The established romance was really sweet to me and I was rooting for them!

There were a few pacing issues and I wish some of the reveals were explained in a different way because it felt info dumpy and I don't think I took it all in.

That said, Overgrowth is a book I will recommending and I am not on a journey to find more alien invasion stories, so thanks to Mira Grant for sending me down this rabbit hole!

Rating: Really Enjoyed It, 4 stars

Overgrowth by Mira Grant is a horror sci-fi in which the vanguard of an alien-plant people is sent to Earth prior an invasion. In this we follow Anastasia Miller...or the plant person who became Anastasia Miller. When she was 3, Stasia went into the forest, and she came back out telling her mother that she was not her daughter but rather the vanguard of an invading species. Now she is in her 30s and working a customer service job in Seattle. She still tells anyone she meets and anyone who asks that she is the vanguard of an invading species and that her people are coming for her. Well, one day an alien signal is intercepted and broadcast around the globe, and people start to ask themselves what if she was not crazy but was actually telling the truth.

This story worked much, much better for me when I stopped expecting it to be horror in the vein of Into the Drowning Deep and started viewing it as a twist on a first-contact story in which we follow the humanized aliens who are also discovering things about their own species for the first time. Is it dark? Certainly. There is a lot of violence and uncertainty as the tension and uncertainty leads to a breakdown of humanity's morals and ethics. There are violent deaths, torture, and a hard look at what humanity is capable of.

I thought that the character work in this is excellent. It does do the thing that I've noticed in some of Seanan McGuire's Wayward Children books where there is a lot of repetition of character traits, but I don't really mind it. I loved the exploration of Stasia's different bonds that she had formed with humans and examining how those evolved and changed with the pressures put in place by the alien invasion and Stasia's role in it.

I thought it was really interesting the way that Stasia compared her experience as an alien who spent her whole life telling people who she really was and not being believed, to her boyfriend, Graham's, experience being a trans man. I also thought that the way that the aliens would have forgone the invasion was very interesting and a commentary on human nature.

I honestly loved the plant people with their biotechnology and the vast diversity of life forms they took on from the different "gardens" that they cultivated across the stars. Honestly I ended up rooting for them by the end - it seemed like they had the better idea of how to live as a harmonious species. Their society seemed a bit of a utopia.

Regardless, I thought this was a super interesting book that is a bit different from my normal sci-fi reads. I personally didn't find it to be a very horror-heavy book, but I am still learning what I like in horror, and it may just be that the tropes/elements in this one don't work as well for me. The pacing was also rather inconsistent, so those are the two things that kept this from being 5 stars.

I listened to the audiobook, and Caitlin Kelly, the narrator did a fantastic job of conveying the emotion and stress of this story. I felt like that definitely added to the story, and kept me engaged even when the pacing was somewhat inconsistent.

I received an advanced listening copy from Netgalley and MacMillan Audio. All thoughts and opinions are my own. Overgrowth releases on May 6, 2025.

Mira Grant (and Seanan McGuire for that matter) is one of my favorite authors to pick up when I need a diverse and inclusive story that keeps me enthralled in the pages. Overgrowth is certainly no different! I was lucky enough to receive the audio book version of the ARC and it was fantastic! I felt I was in the story with Anastasia and Graham as they navigated this near-future world that I could absolutely see happening.

In Overgrowth we find Anastasia as an Alien species who is one of the first colonizers of her kind on planet Earth. She doesn't know much about her alien race other than the fact that they're essentially carnivorous plants and that they are coming and she's a harbinger for them.

This audio book had me itching to listen for the whole week it took me to finish. I even did extra house chores and cut the grass just to have more time with this story! The narrator does a fantastic job of bringing Mira Grant's story to life!

If you want a story about an alien invasion that is totally unique and is based on a plant race, then please make sure to snag this story as soon as it's released on May 6!

Thank you to NetGalley and Macmillan Audio for an ALC of this novel.

I really enjoyed this book and plant based aliens is NOT normally on my list of enjoyment. But I found this very engaging and it kept me fully entertained. A perfect summer sci fi/ horror.

The only issue I had was there was an issue with my ALC and I missed a chunk of chapters in the middle. This was obviously disjointed but still really liked it.

I wasn't a huge fan of the story. the narrator was great and I do enjoy the work of Seanan McGuire. This one just was not for me this time.

The narration was fantastic. Great choice of voice actor. The first and last 20% of the story is great, very exciting and fun. The whole middle 60% however was up and down for me. Way too much dialogue and explanations for my liking. I didn't need to know all that stuff, I certainly wont remember it, and it got boring to sit through. I also feel like a lot of the discussions were repetitive, just had with different people/creatures, It made for a nearly 500 page book that felt like it took me forever finish. I also think describing the book as "full-on body horror" in the synopsis on goodreads is a bit misleading because the body horror is very mild, in my opinion. I was expecting WAY more action. I loved the inclusivity though! The queer rep and diversity amongst the cast was great. Seymour the cat and all of the Little Shop of Horrors references I adored! And the main character Anastasia I loved. I did enjoy the book overall, but its not a favorite by this author.

Thanks so much for access to the alc! As a big fan of Seanan McGuires work, I appreciate it!

Overgrowth follows Anastasia. She’s a young girl who wanders into the woods alone, but when she returns home, she is no longer the real Anastasia.

Alien seeds found their way to Earth and began their journey to invade. The new Anastasia was one of those seeds that made its way to Earth and replaced the old Anastasia, as the seeds nature is designed to do.

What follows is adult Anastasia in a society that has received a strange signal from space.
During this time, we see Stasia as she struggles between her human connections and the roots she truly belongs to.

The alien species here is crafted with such harrowing uniqueness a from how they find planets, develop a ‘forest,’ and eventually transform into their true physical beings.

I had a lot of fun with this book- however, I found myself becoming bored throughout a good 50% of the middle portion. The introduction and ending are close to being 5-star reading moments.
The journey of figuring out how to handle the signal, human relationships changing admit the threat of invasion, and society’s reaction all became repetitive, slow, and felt like a waste of time.

When the plot picked up at around the 70% mark, I immediately became hooked again. No spoilers for this part though! The last 30% is almost exactly what I wanted throughout the entire novel- I just don’t think the slow build-up to get to this point should have taken as long as it did.

Remember that viral video some time ago of the woman on a plane yelling, “I’m telling you right now, that motherf— is not real!”? There’s a scene in this book that reminds me of that, and it was quite a funny part.

I listened to the audiobook, and I believe that tremendously helped me through the middle part. Narration is great in this one!

3 ⭐ overall, but the book definitely has some standout moments.

When Anastasia was three, an incident took place and since then she’s been telling everyone that she is an alien and that her family is coming back for her. Years later after an alien signal is found, people are realizing they were warned of the invasion but didn’t listen. And Anastasia has to make her choices between her family and her adopted home.

Overgrowth was compared to Annihilation and Day of the Triffids. In some ways, I get it. But the difference with Overgrowth is we get the story from the invader, from the body snatcher, this time. Rather than humans trying to come to terms with an invasion, we have a vanguard alien coming to terms with her family returning for her and what to do about this planet she’s spent the majority of her life on. This was an interesting twist on the usual body snatcher stories we get, seeing from the alien perspective. It creates new dilemmas for the character, and it added dimensions to what could have been a predictable story.

Overgrowth was also described as body horror, but if that’s deterred you, don’t let it! This is not truly a body horror book. There are moments of grotesque, and there is some violence, but this is an introspective book as Stasia grapples with her decisions about allegiances. Whether the ties to birth family call to her more than the friends she’s made on her adopted planet. This is also a book about coming to terms with yourself. There is a lot of representation in the book (which is not a surprise if you’ve read anything by the author before!), and it’s not just Stasia who you see have self discovery or affirming stories. There is a lot of depth to the story, and the growth is the primary focus rather than just horror.

The writing, as always, is fantastic. I’ve yet to read a book by the author that I’ve not found beautiful and engaging. Even as an audiobook, the writing pulls you in and you never feel yourself drifting, which is my own personal problem with some audio. The narrator is also great, bringing all of the characters to life.

This is a book I can’t recommend enough, audio or not. It’s such a well written twist on a common story that it’s worth it for every reader who likes alien invasion or body snatcher stories previously. Also, for the Canadian readers - house hippos mentioned, so plus ten stars for that!

Overgrowth is a thought-provoking sci-fi horror with important commentary on otherness and marginalization. While the themes are strong the story struggles with pacing and occasional tone shifts. There was so much potential here, I am curious to see what the author writes next!

Thank you NetGalley and Macmillan Audio for the chance to listen to this title in exchange for my opinion.

I love stories from the alien/villain's POV, especially with a woman character, but this one just didn't live up to the expectation for me.

The first half of the book is really interesting as we inch closer to the alien invasion and Stasia collects her found family. The second half had pacing issues, and the ending felt like Mira didn't quite know how to end it so then we got a flying dinosaur/dragon? It felt too far into fantasy to have the same weight and horror as the first half of the book.

I wish it unpacked the trans rep a little more, the idea of being born in a body that isn't aligned to your identity, I think there's so much similarity between our main character and her trans boyfriend, and then to follow that line through to the horror of transitioning (without consent) into an alien plant monster - I wish that was the story.

Caitlin Kelly does an amazing job as Stasia! I'll definitely be looking for more book narrated by Caitlin.

Ohhh where do I start? This was a very thought provoking read wrapped up in a fun sci fi. I really liked the conversations we were having about immigration and belonging in the beginning. I thought she took a fun invasion trope and really turned it on its head by allowing us to be in the eyes of Stacia the alien and also them announcing their presence. So different than what I usually read. In the second half when the invasion happens, I expected the horror to really kick in. Instead, I found the pacing slowed down more for me and became a little repetitive. This definitely is a more literary sci-fi than horror in my opinion. I still really enjoyed this, but I do wish the second half had leaned into the horror more kind of like Into the Drowning Deep.

The narrator did a great job on this one! Especially with the alien language and such. I would definitely recommend the audio.

Overgrowth is a creepy and engaging SciFi that is incredibly topical. Mira Grant really hits the nail on the head when discussion topics relevant to todays political climate. Anastasia Miller was such an interesting character and how her experience being a seedling that was planted by an Alien Race and how it correlates with Trans People and Immigrants. The fact that people were so willing to brush off her warnings because it "it wasn't hurting anyone" and then turn around to invalidate Grahams identity Transman or Mandy being Biracial.

Mira Grant always delivers in the SciFi genre by applying real world situations into a digestible story that has a lot of heart. I also like that this had a really sweet romance element.

The narrator also did a really good job at giving voice to Anastasia and developing the world as described, a solid performance.

Overall a really good read! Will recommend

'Family is where you keep the pieces of yourself that need to be shared with someone else if they’re going to have meaning, the memories that must be seen from three or four different angles at the same time before they find their context.'

Anastasia Miller is an alien, and the invasion is coming. I am absolutely blown away by this incredible story. At it's core, this is a story about choice, morals, and love. I had ZERO expectations of shedding tears when I went into this, but here we are. While this was a complex story with the internal intricacies, it was also an incredibly eerie read about an actual alien invasion.
This was a slow burn that was overflowing with character development. Anastasia's relationship with her boyfriend Graham was beautiful. The love and support they had for each other was nothing short of unconditional. The friendships created and developed were incredibly thoughtful. While the world was burning around everyone, those chose to be ride or dies together, and I thought that was so powerful.
There were parts of the story that I thought were slower moving, but none of it took away from the overall big picture. I had a fantastic time listening to this. I enjoyed this far more than I ever thought I would, and this instilled some hope in humanity for me.
So many thanks to Macmillan for this ALC!

Ahoy there me mateys!  Mira Grant is the pen name for Seanan McGuire's sci-fi & horror tales.  This is her newest about an alien invasion coming soon to an Earth near you.  When Anastasia "Stasia" Miller was three years old, she got lost in the woods and was enticed by a weird alien plant.  When she immerges several days later, she tells everyone that she is an alien in disguise as a human and that the armada is coming.  No one believes her.

Except Stasia is telling the truth.  The alien plant has consumed her human self and taken her place.  She has no other facts about the invasion.  No timeline.  No idea what she is supposed to do in the meantime.  And no choice but to keep repeating the truth of her nature to everyone she meets.  Needless to say, she isn't extremely popular.

Stasia has a handful of friends, a boyfriend named Graham, and a cat named Seymour who tolerate her alien quirkiness.  Then one day, an alien signal is received by Earth.  The invasion is finally coming to pick Stasia up.  Humans are beginning to believe in aliens.  The government is involved.  And Stasia finds others of her kind.  That is just the beginning of Stasia's crazy adventure and the take down of Earth.

I began reading this in e-book form and switched to the audiobook.  I absolutely loved the set-up for this novel.  Reading about Stasia's disappearance, return, and foray into human adulthood was fascinating.  There is a bit of body horror involving the plant and it was creepy and awesome.  I also loved when Stasia realized that there were other aliens like her planted (ha!) on Earth.

Unfortunately for me, I felt that this book was not as interesting once the alien signal was introduced.  And when the government gets involved around the 38% mark I was less than enthused.  I think this is because the novel went from a focus on character relationships to a more action novel flavor.  Also Stasia really spends a lot of time waffling about the same existential questions.  Because she and the other aliens don't really know anything about what the invasion will do, the reader has to spend a lot of time just waiting alongside them. 

Once invasion day starts (62%), the pace picked back up again.  I enjoyed a lot Stasia and the other aliens interactions with the invaders.  I appreciated how Earth's humans were never going to win.  But I found the overall goals of the aliens to be rather silly.  About a third of this book really floated my boat so I am glad I read it and I have been thinking about it a lot.  I just think that the majority of this book wasn't to my personal taste.  Arrrr!

Side note: what actually happened to Seymour?  Did I miss where he ended up?

Overgrowth is the kind of explosive monster horror we've come to expect from Mira Grant. The audiobook is immersive with clear voices. It does lean on the long side, but is a fun and engaging read nonetheless.

Three-year-old Anastasia Miller wandered into the woods and never returned home. Something came back — something that looked like Anastasia, talked like Anastasia, but insisted she was an alien, a scout left behind by her people, waiting for the day they’d return. Like a cuckoo chick in a human nest, she grew up with Earth’s cultural literacy but knowing she belonged somewhere else.

Now, years later, a signal from the stars confirms her story. The armada is coming. But it’s not a joyous reunion — it’s an invasion. And as humanity scrambles to respond, Stasia and a mismatched group of allies must decide what to do when the future you’ve been waiting for turns out to be a threat to everything you've learned to love.

Despite the knowledge at the outset that an alien invasion is impending, this is a slower, more introspective story rather than a high-octane thriller or horror story. There are interesting ideas at play in the book. Stasia’s perspective as someone caught between two worlds — biologically alien, emotionally tied to Earth — is compelling, and the glimpses we get of the alien species, especially the psychic bond between the scouts and the lush design of the vessel, are fresh and evocative. But ultimately, the execution didn’t quite land (ha ha) for me.

The pacing is a big part of that. I had access to both the audiobook and eBook through my review copy, and at one point, I realized the audiobook was missing a significant chunk of chapters — and I hadn’t noticed. I feel like that's the best way I can convey how uneven the structure and momentum felt. The early promise of an alien arrival kept getting delayed by scenes that didn’t add much urgency or emotional weight, and much of the final act relies on lengthy conversations rather than truly gripping confrontation.

Tone-wise, Overgrowth is earnest and readable, but it didn’t feel especially distinctive in a crowded sci-fi field. For me, this was a solid concept with uneven execution — a read that I wanted to like more than I actually did. Plenty of other readers seem to enjoy this one, though, so maybe my complaints about the pacing are a matter of personal preference.

Thank you to netgalley and the publisher for an early copy in exchange for an honest review.

Audio: the audio is fitting, feels like it represents the character well, and brings the story to life.

Review: I really enjoyed this book. I didn't think I was going to because sci-fi is very hit or miss for me. However, I really, really enjoyed this book. I've wanted to try Mira Grant for a long time and this definitely makes me want to read other works by her. The plot is straight forward, engaging, and exactly what the synopsis says it's going to be. The book is consistent the entire way through, pacing is perfect. I also really enjoyed the characters and their stories. The diverse representation was much appreciated, as a trans guy myself, we don't get a lot of stories about transmen and ciswomen together. Overgrowth has a lot to say, so much you should read it yourself, I can't really do it justice in my review. There's a lot of social commentary but Grant does it in a way that weaves it throughout the story and will feel relatable for most of us. Really glad I read this. The MC is endearing and one I will continue to think about. I could see myself reading this again in the future.

The stunning cover and fantastic concept caught me. I expected science fiction horror with the tight, suspenseful writing that captivated me in the two Rolling in the the Deep books. This novel has an interesting vision and some magical moments, yet I struggled to engage with it. I think I'm simply not part of the target  audience.

An early, grisly scene that may be disturbing for some readers felt like the beginning of a horrific experience. instead, most of the book had a very young tone, a slow pace, and an emphasis on found family. For me, there was too much spoon-feeding and repetition of explanations. I prefer to feel immersed and discover what's going on via action and dialogue.

I liked the creepy plant moments and interractions with aliens. I wish there'd been more of that.

I strongly recommend the audiobook. The vocal performance helps to add interest and the narrator speaks clearly. The production values are excellent.
Thank you, Macmillan Audio, for the ALC via NetGalley for consideration. These opinions are solely my own.

This is pretty long, but it's Mira Grant, so I stopped what I was supposed to be doing so I could read this first. Mira Grant has such a wild imagination and all her books are so different -- I've been reading her since Feed, her zombie series, and there are so many other worlds she has created. This story is darkly hilarious -- the real Anastasia Miller was murdered when she was three and replaced by an alien, and she has spent her whole life telling everyone that she is an alien and her people are on their way.
Even her friends don't believe her, which makes sense -- even though she's an odd person, she still has a normal life with a job and a boyfriend and friends. When the aliens finally do arrive, the pace picks up, and there are so many questions about what makes us human and how we are tied to each other. Thanks to NetGalley, I got to listen to the audiobook, which is excellent, and the voice was perfect for Anastasia.